Burning smell when going uphill

I have a 1999 Chevy Prizm which I bought new back then. About two years into driving it I noticed a burned sort of smell every time I drove uphill (I live in western Montana). Not like burned oil, more the tar smell variety. Over the years it’s gotten worse. I can avoid the smell if I do like a semi driver and let the car slow down to about 50 or 55 mph. The car burns a small amount of oil - about half to one quart of oil between oil changes (every 4,000 miles or so). Also, the dip stick seems to smell like gasoline when I check the oil, especially when the engine is still warm. Cracked gasket maybe?

If the car appears to run well with no Check Engine Light being illuminated you might consider a leaking fuel pressure regulator (easily tested) as possibly being responsible for the gasoline smell in the oil.
Gas diluted oil is not good for an engine and I don’t know what to say about putting up with this for approx. 8 years.

The smell could also be related to a slipping clutch if the car has a manual transaxle although one would wonder how it has also survived 8 years like this.